题目8：求s=a+aa+aaa+aaaa+aa...a的值，其中a是一个数字。例如



2+22+222+2222+22222(此时共有5个数相加)，几个数相加有键盘控制。

-Title 8: o s = a+ aa+ aaa+ aaaa+ aa... A value, of which a is a number. For example



2+ and+ 222+ 2222+ 22222 (the five number additive), a few number additive has the keyboard control.